Sakho enjoyed an impressive loan spell with the Eagles last season, playing his part in a side that collected 16 points from seven games before his season was ended with a knee injury in the 1-0 defeat to Tottenham on April 26.

The impressive run of form included four clean sheets and victories against Arsenal and Chelsea, and Palace were expected to try and negotiate a permanent deal prior to Sam Allardyce's departure at the end of the campaign.